The development of a suite of programs for the analysis of mechanisms

Abstract

Consideration of the practical-design office approach to the design of mechanisms has led the author to propose and develop an interactive kinematic program package for computer aided design (CAD). All mechanism elements can be defined with up to six degrees-of-freedom before they are assembled within a designated area of the mechanism drawing file. Variations of these freedoms, to provide the desired mechanism movements, are held within a data file and employed in the construction of graphical representations in other designated areas within this mechanism file. Translations and rotations of elements can be imposed by the insertion of discreet values into the data file, by movement of elements at selectedly viewed “frames” during the mechanism cycle, or by movement (or definition) of the graphical function lines. Changes caused by one mode of entry are automatically reflected in all others. Mechanisms can thus be assembled by the linking of elements, run through their operating cycle, and changed until desired motions are obtained. These procedures are illustrated through their application to the kinematic analysis of an industrial sewing machine needle drive mechanism.